controller.go

/*
Copyright 2020 Critical Stack, LLC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package controllers

import (
	"context"
	"fmt"
	"time"

	configutil "github.com/criticalstack/crit/pkg/config/util"
	critv1 "github.com/criticalstack/crit/pkg/config/v1alpha2"
	"github.com/go-logr/logr"
	"github.com/pkg/errors"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	kerrors "k8s.io/apimachinery/pkg/util/errors"
	"k8s.io/client-go/tools/record"
	clusterv1 "sigs.k8s.io/cluster-api/api/v1alpha3"
	capierrors "sigs.k8s.io/cluster-api/errors"
	"sigs.k8s.io/cluster-api/util"
	"sigs.k8s.io/cluster-api/util/patch"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/handler"
	"sigs.k8s.io/controller-runtime/pkg/source"

	controlplanev1 "github.com/criticalstack/cluster-api-bootstrap-provider-crit/apis/controlplane/v1alpha2"
	"github.com/criticalstack/cluster-api-bootstrap-provider-crit/internal"
	"github.com/criticalstack/cluster-api-bootstrap-provider-crit/internal/remote"
)

// CritControlPlaneReconciler reconciles a CritControlPlane object
type CritControlPlaneReconciler struct {
	client.Client
	Log    logr.Logger
	Scheme *runtime.Scheme

	controller         controller.Controller
	recorder           record.EventRecorder
	remoteClientGetter remote.ClusterClientGetter

	managementCluster internal.ManagementCluster
}

func (r *CritControlPlaneReconciler) SetupWithManager(mgr ctrl.Manager, options controller.Options) error {
	c, err := ctrl.NewControllerManagedBy(mgr).
		For(&controlplanev1.CritControlPlane{}).
		Owns(&clusterv1.Machine{}).
		Watches(
			&source.Kind{Type: &clusterv1.Cluster{}},
			&handler.EnqueueRequestsFromMapFunc{
				ToRequests: handler.ToRequestsFunc(r.ClusterToCritControlPlane),
			},
		).
		WithOptions(options).
		Build(r)
	if err != nil {
		return errors.Wrap(err, "failed setting up with a controller manager")
	}
	r.Scheme = mgr.GetScheme()
	r.controller = c
	r.recorder = mgr.GetEventRecorderFor("crit-control-plane-controller")
	if r.remoteClientGetter == nil {
		r.remoteClientGetter = remote.NewClusterClient
	}
	if r.managementCluster == nil {
		r.managementCluster = &internal.Management{Client: r.Client}
	}
	return nil
}

// +kubebuilder:rbac:groups=core,resources=events,verbs=get;list;watch;create;patch
// +kubebuilder:rbac:groups=core,resources=secrets,verbs=get;list;watch;create;patch
// +kubebuilder:rbac:groups=core,resources=configmaps,namespace=kube-system,verbs=get;list;watch;create
// +kubebuilder:rbac:groups=rbac,resources=roles,namespace=kube-system,verbs=get;list;watch;create
// +kubebuilder:rbac:groups=rbac,resources=rolebindings,namespace=kube-system,verbs=get;list;watch;create
// +kubebuilder:rbac:groups=infrastructure.cluster.x-k8s.io;bootstrap.cluster.x-k8s.io;controlplane.cluster.x-k8s.io,resources=*,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=cluster.x-k8s.io,resources=clusters;clusters/status,verbs=get;list;watch
// +kubebuilder:rbac:groups=cluster.x-k8s.io,resources=machines;machines/status,verbs=get;list;watch;create;update;patch;delete

func (r *CritControlPlaneReconciler) Reconcile(req ctrl.Request) (res ctrl.Result, reterr error) {
	ctx := context.Background()
	logger := r.Log.WithValues("namespace", req.Namespace, "critcontrolplane", req.NamespacedName)

	// Fetch the CritControlPlane instance.
	ccp := &controlplanev1.CritControlPlane{}
	if err := r.Client.Get(ctx, req.NamespacedName, ccp); err != nil {
		if apierrors.IsNotFound(err) {
			return ctrl.Result{}, nil
		}

		// Error reading the object - requeue the request.
		logger.Error(err, "Failed to retrieve requested CritControlPlane resource from the API Server")
		return ctrl.Result{Requeue: true}, nil
	}

	// Fetch the Cluster.
	cluster, err := util.GetOwnerCluster(ctx, r.Client, ccp.ObjectMeta)
	if err != nil {
		logger.Error(err, "Failed to retrieve owner Cluster from the API Server")
		return ctrl.Result{}, err
	}
	if cluster == nil {
		logger.Info("Cluster Controller has not yet set OwnerRef")
		return ctrl.Result{}, nil
	}

	logger = logger.WithValues("cluster", cluster.Name)

	if util.IsPaused(cluster, ccp) {
		logger.Info("Reconciliation is paused")
		return ctrl.Result{}, nil
	}

	// Wait for the cluster infrastructure to be ready before creating machines
	if !cluster.Status.InfrastructureReady {
		return ctrl.Result{}, nil
	}

	// Initialize the patch helper.
	patchHelper, err := patch.NewHelper(ccp, r.Client)
	if err != nil {
		logger.Error(err, "Failed to configure the patch helper")
		return ctrl.Result{Requeue: true}, nil
	}

	defer func() {
		if requeueErr, ok := errors.Cause(reterr).(capierrors.HasRequeueAfterError); ok {
			if res.RequeueAfter == 0 {
				res.RequeueAfter = requeueErr.GetRequeueAfter()
				reterr = nil
			}
		}
		// Always attempt to update status.
		if err := r.updateStatus(ctx, ccp, cluster); err != nil {
			logger.Error(err, "Failed to update CritControlPlane Status")
			reterr = kerrors.NewAggregate([]error{reterr, err})
		}

		// Always attempt to Patch the CritControlPlane object and status after each reconciliation.
		if err := patchHelper.Patch(ctx, ccp); err != nil {
			logger.Error(err, "Failed to patch CritControlPlane")
			reterr = kerrors.NewAggregate([]error{reterr, err})
		}

		// TODO: remove this as soon as we have a proper remote cluster cache in place.
		// Make CCP to requeue in case status is not ready, so we can check for node status without waiting for a full resync (by default 10 minutes).
		// Only requeue if we are not going in exponential backoff due to error, or if we are not already re-queueing, or if the object has a deletion timestamp.
		if reterr == nil && !res.Requeue && !(res.RequeueAfter > 0) && ccp.ObjectMeta.DeletionTimestamp.IsZero() {
			if !ccp.Status.Ready {
				res = ctrl.Result{RequeueAfter: 20 * time.Second}
			}
		}
	}()

	if !ccp.ObjectMeta.DeletionTimestamp.IsZero() {
		return r.reconcileDelete(ctx, cluster, ccp)
	}
	obj, err := configutil.Unmarshal([]byte(ccp.Spec.CritConfigSpec.Config))
	if err != nil {
		return ctrl.Result{}, err
	}
	cfg, ok := obj.(*critv1.ControlPlaneConfiguration)
	if !ok {
		return ctrl.Result{}, errors.Errorf("expected ControlPlaneConfiguration, received %T", obj)
	}
	return r.reconcileControlPlane(ctx, cluster, ccp, cfg)
}

// ClusterToCritControlPlane is a handler.ToRequestsFunc to be used to enqeue
// requests for reconciliation for CritControlPlane based on updates to a
// Cluster.
func (r *CritControlPlaneReconciler) ClusterToCritControlPlane(o handler.MapObject) []ctrl.Request {
	c, ok := o.Object.(*clusterv1.Cluster)
	if !ok {
		r.Log.Error(nil, fmt.Sprintf("Expected a Cluster but got a %T", o.Object))
		return nil
	}

	controlPlaneRef := c.Spec.ControlPlaneRef
	if controlPlaneRef != nil && controlPlaneRef.Kind == "CritControlPlane" {
		name := client.ObjectKey{Namespace: controlPlaneRef.Namespace, Name: controlPlaneRef.Name}
		return []ctrl.Request{{NamespacedName: name}}
	}

	return nil
}